A case series of patients with lamotrigine toxicity at one center from 2003 to 2012

Unexpected Seizure Activity in the Setting of Lamotrigine Toxicity

Lamotrigine, a widely utilized broad-spectrum anticonvulsant, is commonly prescribed for epilepsy management and bipolar mood disorders. Despite its extensive clinical usage, instances of lamotrigine overdose are underreported. Here, we present a case involving acute encephalopathy and seizure onset following an intentional lamotrigine overdose. This case underscores the importance of recognizing the potential clinical manifestations of lamotrigine toxicity, such as encephalopathy and seizures, emphasizing the necessity for vigilant management of patients receiving this medication.

Gene mutations in comorbidity of epilepsy and arrhythmia

Epilepsy is one of the most common neurological disorders, and sudden unexpected death in epilepsy (SUDEP) is the most severe outcome of refractory epilepsy. Arrhythmia is one of the heterogeneous factors in the pathophysiological mechanism of SUDEP with a high incidence in patients with refractory epilepsy, increasing the risk of premature death. The gene co-expressed in the brain and heart is supposed to be the genetic basis between epilepsy and arrhythmia, among which the gene encoding ion channel contributes to the prevalence of "cardiocerebral channelopathy" theory. Nevertheless, this theory could only explain the molecular mechanism of comorbid arrhythmia in part of patients with epilepsy (PWE). Therefore, we summarized the mutant genes that can induce comorbidity of epilepsy and arrhythmia and the possible corresponding treatments. These variants involved the genes encoding sodium, potassium, calcium and HCN channels, as well as some non-ion channel coding genes such as CHD4, PKP2, FHF1, GNB5, and mitochondrial genes. The relationship between genotype and clinical phenotype was not simple linear. Indeed, genes co-expressed in the brain and heart could independently induce epilepsy and/or arrhythmia. Mutant genes in brain could affect cardiac rhythm through central or peripheral regulation, while in the heart it could also affect cerebral electrical activity by changing the hemodynamics or internal environment. Analysis of mutations in comorbidity of epilepsy and arrhythmia could refine and expand the theory of "cardiocerebral channelopathy" and provide new insights for risk stratification of premature death and corresponding precision therapy in PWE.

A systematic review of the effectiveness and safety of droperidol for pediatric agitation in acute care settings

OBJECTIVE

Agitation in children in acute care settings poses significant patient and staff safety concerns. While behavioral approaches are central to reducing agitation and oral medications are preferred, parenteral medications are used when necessary to promote safety. The goal of this systematic review was to evaluate the effectiveness and safety of an ultra-short-acting parenteral medication, droperidol, for the management of acute, severe agitation in children in acute care settings.

METHODS

A systematic review of randomized controlled trials, observational studies, and case series/reports examined the effectiveness and safety of parenteral droperidol for management of acute agitation in patients ≤21 years old in acute care settings. Effectiveness outcomes included time to sedation and need for a subsequent dose of medication. Safety outcomes were adverse effects such as QTc prolongation, hypotension, respiratory depression, and dystonic reactions.

RESULTS

A total of 431 unique articles were identified. Six articles met inclusion criteria: two in the prehospital setting, one in the emergency department, and three in the inpatient hospital setting. The articles included a prospective observational study, three retrospective observational studies, and two case reports. The largest study reported a median time to sedation of 14 min (interquartile range 10-20 min); other studies reported a time to sedation of 15 min or less. Across studies, 8%-22% of patients required a second dose of medication for ongoing agitation. The most frequent adverse effects were dystonic reactions and transient hypotension. One patient had QTc prolongation and another developed respiratory depression, but both had significant comorbidities that may have contributed. The risk of bias in included studies ranged from moderate to critical.

CONCLUSIONS

Existing data on droperidol for management of acute agitation in children suggest that droperidol is both effective and safe for acute, severe agitation in children. Data are limited by study designs that may introduce bias.

Epilepsy-Induced High Affinity Blockade of the Cardiac Sodium Current INa by Lamotrigine; A Potential for Acquired Arrythmias

Lamotrigine is widely prescribed to treat bipolar neurological disorder and epilepsy. It exerts its antiepileptic action by blocking voltage-gated sodium channels in neurons. Recently, the US Food and Drug Administration issued a warning on the use of Lamotrigine after observations of conduction anomalies and Brugada syndrome patterns on the electrocardiograms of epileptic patients treated with the drug. Brugada syndrome and conduction disturbance are both associated with alterations of the cardiac sodium current (I_Na) kinetics and amplitude. In this study, we used the patch clamp technique on cardiomyocytes from epileptic rats to test the hypothesis that Lamotrigine also blocks I_Na in the heart. We found that Lamotrigine inhibited 60% of I_Na peak amplitude and reduced cardiac excitability in epileptic rats but had little effect in sham animals. Moreover, Lamotrigine inhibited 67% of I_NaL and, more importantly, prolonged the action potential refractory period in epileptic animals. Our results suggest that enhanced affinity of Lamotrigine for I_Na may in part explain the clinical phenotypes observed in epileptic patients.

The assessment of cardiac risk in patients taking lamotrigine; a systematic review

OBJECTIVE

The Food and Drug Administration (FDA) warned about lamotrigine's arrhythmogenicity based on in vitro data. This systematic review investigates lamotrigine's effect on cardiac conduction and risk of sudden cardiac death (SCD) in individuals with and without cardiovascular disease.

METHODS

We searched Web of Science and PubMed from inception through August 2021. We included studies measuring electrocardiogram (ECG) changes, laboratory abnormalities, or SCD among patients taking lamotrigine. Studies examining sudden unexpected death in epilepsy were excluded for scope. Two reviewers assessed articles and extracted data. We used the Effective Public Healthcare Panacea Project tool to evaluate confidence in evidence.

RESULTS

Eight randomized controlled trials, 9 nonrandomized observational studies, and 24 case reports were identified, with >3054 total participants, >1606 of whom used lamotrigine. One randomized trial of older patients found an average QRS increase of 3.5 +/- 13.1 ms. Fifteen studies reported no changes in ECG parameters. Case reports documented QRS widening (13), Brugada syndrome (6), QTc prolongation (1) and SCD (2), though many ingested toxic quantities of lamotrigine and/or other medications.

CONCLUSIONS

Evidence is insufficient to support the breadth of the FDA warning concerning lamotrigine's cardiac risk. Lamotrigine at therapeutic doses may be associated with modest, non-dangerous QRS widening.

A tiered approach to population-based in vitro testing for cardiotoxicity: Balancing estimates of potency and variability

Population-wide in vitro studies for characterization of cardiotoxicity hazard, risk, and population variability show that human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are a powerful and high-throughput testing platform for drugs and environmental chemicals alike. However, studies in multiple donor-derived hiPSC-CMs, across large libraries of chemicals tested in concentration-response are technically complex, and study design optimization is needed to determine sufficient and fit-for-purpose population size considerations. Therefore, we tested a hypothesis that a computational down-sampling analysis based on the data from hiPSC-CM screening of 136 diverse compounds in a population of 43 non-diseased donors, including multiple replicates of the "standard" donor hiPSC-CMs, will inform optimal study designs depending on the decision context (hazard, risk and/or inter-individual variability in cardiotoxicity). Through 50 independent random subsamples of 5, 10, or 20 donors, we estimated accuracy and precision for quantifying potency, inter-individual variability, and QT prolongation risk; the results were compared to the full 43-donor cohort. We found that for potency and clinical risk of QT prolongation, a cohort of 5 randomly-selected unique donors provides accurate and precise estimates. Larger cohort sizes afforded marginal improvements, and 5 replicates of a single donor performed worse. For estimating inter-individual variability, cohorts of at least 20 donors are needed, with smaller populations on average showing bias towards underestimation in population variance. Collectively, this study shows that a variable-size hiPSC-CM-based population-wide in vitro model can be used in a number of decision scenarios for identifying cardiotoxic hazards of drugs and environmental chemicals in the population context.

Successful management of massive lamotrigine extended-release intoxication in a dog

A 3-year-old spayed female Siberian Husky presented for evaluation following ingestion of approximately 429 mg/kg of lamotrigine extended-release. She demonstrated severe neurologic and cardiac signs and was treated with lipid emulsion, anticonvulsants, antiarrhythmics and aggressive decontamination and supportive care. She was successfully discharged from the hospital 5 days later.

Data on the relationship between lamotrigine and levetiracetam serum/plasma levels and toxicity: Experience at an academic medical center

Lamotrigine and levetiracetam are second-generation anti-epileptic drugs used for the management of seizure disorders and some other medical conditions. In the related research article using retrospective data from an academic medical center, we analyzed 5046 samples originating from 1930 unique patients that had lamotrigine drug levels performed on serum/plasma and 4359 samples from 2451 patients that had levetiracetam drug levels performed. The data in this article provides the patient demographic, clinical location at time of drug level, and specific lamotrigine or levetiracetam serum/plasma drug level for all patients. For those instances with lamotrigine drug level greater than 14.0 mg/L or levetiracetam drug level of 80 mg/L or higher, additional data from chart review includes: indication for ordering the drug level, two main presenting signs or symptoms at time of drug level, timing of drug level (random, trough, peak, or unknown), changes in drug dosing following the drug level, concomitant therapy with valproic acid (lamotrigine only), and details related to drug overdose (if applicable). The analyzed data is provided in the supplementary tables included in this article. Volumes of test ordering by year is included in a figure. The dataset reported is related to the research article entitled "Correlation of Elevated Lamotrigine and Levetiracetam Serum/Plasma Levels with Toxicity: A Long-Term Retrospective Review at an Academic Medical Center" [K. E. Wood, K. L. Palmer, M.D. Krasowski, Correlation of elevated lamotrigine and levetiracetam serum/plasma levels with toxicity: A long-term retrospective review at an academic medical center, Toxicol. Rep. (2021) 8:1592-1598].

Escitalopram, bupropion, lurasidone, lamotrigine and possible vortioxetine overdose presented with serotonin syndrome and diffuse encephalopathy: A case report

BACKGROUND

Psychotropic drugs can cause neurological effects when overdosed. This study reports a case of psychotropic drugs overdose presenting with serotonin toxicity and encephalopathy.

CASE PRESENTATION

A 20-year-old female with major depression presented with agitation 3 h after an overdose on multiple medications. Her current medications were vortioxetine, lamotrigine, lurasidone, and bupropion (extended-release). Vital signs showed hyperthermia and tachycardia. Neurological examination was remarkable for mydriasis and hyperreflexia with inducible ankle clonus. The electrocardiography showed sinus tachycardia with QTc 480 ms. Twelve hours later, she became obtunded and developed subcortical myoclonus. The electroencephalogram demonstrated a diffuse encephalopathy pattern without epileptic activities. She was diagnosed with serotonin syndrome based on Hunter Serotonin Toxicity Criteria. Myoclonus and abnormal vital signs resolved within hours after cyproheptadine administration, but she remained unconscious for 3.5 days. Urine drug screening was positive for benzodiazepines and metabolites, lamotrigine, escitalopram, and hydroxybupropion. This suggested she had overdosed on escitalopram which had been previously prescribed. Unfortunately, vortioxetine and lurasidone could not be detected by our current facilities.

CONCLUSION

This case exhibited serotonin syndrome and encephalopathy from overdose of multiple psychotropic agents. Her prolonged depressed consciousness could be explained by the half-life of the drugs and possible drug interactions.

Lamotrigine-Associated Movement Disorder: A Literature Review

BACKGROUND

Lamotrigine (LMT) is a phenyltriazine derivative that was originally described as an antiepileptic drug.

OBJECTIVE

This literature review aims to evaluate the clinical epidemiological profile, pathological mechanisms, and management of lamotrigine-associated movement disorders.

METHODS

Relevant reports in six databases were identified and assessed by two reviewers without language restriction. Reports that the individuals only developed tremor or ataxia after LMT use were not included.

RESULTS

In total 48 reports of 108 cases from 19 countries were assessed. The movement disorders associated with LMT found were 29 tics, 21 dyskinesias, 14 myoclonus, 13 parkinsonism, 10 dystonia, and 1 stuttering. The not clearly defined cases included 10 akathisia, 4 myoclonus, 4 cerebellar syndromes, 1 hypertonia, 1 dyskinesia, and an unknown number of dystonia cases. The mean reported age was 33.34 years (range: 1.574 years). The male was the predominant sex and the most common LMT indication was epilepsy. The mean LMT-dose at the movement disorder onset was 228 mg. The time from LMT start to the onset of movement disorder was within 6 months in 81%. The time from LMT withdrawal to complete recovery was within 1 month in 83%. The most common management was LMT withdrawal.

CONCLUSIONS

In the literature, the majority of the cases did not give a clear picture of the individual, and the times of movement disorder onset and recovery are not described. We believe that before withdrawal LMT, a dose adjustment based on the benefits and adverse events with careful evaluation case-by-case can be done.

Correlation of elevated lamotrigine and levetiracetam serum/plasma levels with toxicity: A long-term retrospective review at an academic medical center

Lamotrigine and levetiracetam are widely used second-generation anti-epileptic drugs. Existing literature indicates that overdose of either drug is typically benign, but neurologic and cardiac toxicity can occur in some cases. In this retrospective study, we analyzed a large dataset of serum/plasma drug levels for lamotrigine and levetiracetam. The data covered 1,930 unique patients (5,046 levels) for lamotrigine and 2,451 patients (4,359 levels) for levetiracetam. We performed detailed chart review on all patients with one or more lamotrigine levels greater than 14.0 mg/L (293 unique patients) and all patients with one or more levetiracetam levels of 80 mg/L or higher (106 unique patients). No deaths directly attributable to lamotrigine or levetiracetam toxicity were reported. For cases with lamotrigine levels greater than 14.0 mg/L, the majority of patients were asymptomatic (55.3 %, n = 162). The most common presenting symptoms were ataxia (14.3 %, n = 42), seizures (14.0 %, n = 41), dizziness (11.9 %, n = 35), and altered mental status (11.6 %, n = 34). There were 12 overdoses (11 intentional) involving lamotrigine, all of which presented with either altered mental status (n = 8) or seizures (n = 4). The highest estimated dose reportedly ingested was 20 g. Cardiac toxicity was observed in two cases involving intentional overdose of lamotrigine. For patients with levetiracetam serum/plasma levels of 80 mg/L or higher, 48 patients (45.3 %) were asymptomatic. Symptomatic patients most commonly presented with seizures (31.1 %, n = 33) and altered mental status (15.1 %, n = 16), and none showed cardiac symptoms. There were only two cases involving intentional levetiracetam overdose, one of which presented with altered mental status after ingestion of 45 g and the other asymptomatic after ingestion of 6 g. Overall, our data is consistent with previous investigations that lamotrigine and levetiracetam toxicity most typically presents with neurologic symptoms and rarely cardiac arrhythmias. Approximately half of the patients with elevated lamotrigine or levetiracetam drug levels are asymptomatic.

Effectiveness of multiple-dose activated charcoal in lamotrigine poisoning: a case series

INTRODUCTION

Lamotrigine toxicity can cause coma, seizures, and intraventricular conduction disturbances, and treatment options include good supportive care. We report two cases of lamotrigine poisoning in which multiple-dose activated charcoal may have shortened the elimination half-life of lamotrigine.

CASE 1

A 21-year-old woman ingested 15.6 g lamotrigine, 14 g levetiracetam, and 15 mg clonazepam. She became comatose and developed generalized tonic seizure. One hour post-ingestion, 50 g activated charcoal was administered. Starting 11 h post-ingestion, 25 g activated charcoal was administered every 4 h for 4 doses. The peak concentration of serum lamotrigine was 49.5 µg/mL, and the elimination half-life after commencement of multiple-dose activated charcoal was 6.5 h.

CASE 2

A 46-year-old woman ingested 0.3 g lamotrigine and 0.1 g topiramate twice, 2 h apart. She became drowsy, complained of blurred vision, vertigo, nausea, and vomited. An initial dose of 50 g activated charcoal was administered at 4.5 h post-second ingestion, and subsequent doses of 25 g (total of 3 doses) were administered every 4 h, commencing at 8.5 h post-second ingestion. The peak concentration of serum lamotrigine was 19.9 µg/mL, and the elimination half-life after commencement of multiple-dose activated charcoal was 9.3 h.

DISCUSSION

The mean elimination half-life of lamotrigine in healthy volunteers and epileptic patients receiving lamotrigine monotherapy is 22.8-37.4 h. In our two cases, multiple-dose activated charcoal may have shortened the elimination half-life of lamotrigine, possibly by inhibiting enterohepatic circulation. Multiple-dose activated charcoal should be considered an option for treating lamotrigine poisoning.

Antiepileptic drugs and serotonin syndrome- A systematic review of case series and case reports

Serotonin syndrome (SS) is a drug‑induced, potentially fatal, clinical syndrome resulting from drugs that have serotonergic properties. Several antiepileptic drugs (AEDs) are known to have serotonergic properties and it can be hypothesized that such AEDs can cause SS. This study aims to review the literature on SS in patients receiving AEDs. We performed a systematic review of Scopus and MEDLINE/PUBMED for case reports and case series of SS where patients had received at least one AED at the onset of symptoms. The cases published in the English literature between 1 January 1991 and 1 April 2021 were included. Initial search identified 1263 articles of which 63 (76 patients) were included in the final analysis. Most of the included cases (53 cases, 70%) have been published in the last 10 years. The mean age of the 76 patients was 40.6 ± 17.8 years, and 51% of cases were females. These patients had been exposed to a total of 8 different types of AEDs. Valproic acid was the most common drug (29, 38%), followed by lamotrigine (22, 29%), gabapentin (16, 21%), pregabalin (seven, 9%), topiramate (five, 7%) and carbamazepine (two, 3%). There has been one case each with phenytoin and oxcarbazepine. Seven (9%) patients received more than one AEDs. Most patients (67, 88%) also received other serotoninergic agents. Only nine (12%) patients were on AEDs alone. The most common clinical condition for using AEDs was psychiatric disorders (36 patients, 47.3%), followed by migraine (17, 22.4%), other painful conditions (15, 19.7%), epilepsy (7, 9.2%), and perioperative conditions (8, 10.5%). Death was reported in two patients. We suggest that AEDs, because of their serotonergic properties, may induce SS, especially in patients who are on another serotonergic agent.

Lamotrigine Toxicosis Treated with Intravenous Lipid Emulsion Therapy in a Dog

A female spayed dachshund/mixed-breed dog was evaluated following ingestion of lamotrigine tablets with subsequent rapid onset of vomiting, diarrhea, and generalized tremoring. On initial examination, the dog was moderately obtunded and nonambulatory with intermittent myoclonus and hyperesthesia. Electrocardiogram revealed sinus tachycardia with prolongation of the QT interval. Intravenous lipid emulsion (ILE) infusion was initiated, with reduction in tremoring and improved patient mentation being noted after ∼20 min of therapy. An elevated cardiac troponin I value measured at 1.02 ng/mL the day after presentation. Serum toxicological assay revealed marked reduction in serum lamotrigine levels following ILE and continued reduction during hospitalization. The dog's clinical signs resolved, corrected QT interval returned to normal, and the patient was discharged 38 hr after presentation. Individual cases of lamotrigine toxicosis have not been fully reported in veterinary literature. This case report documents the rapid onset of clinical signs including neurologic dysfunction, cardiac arrhythmias, and transient corrected QT prolongation. Serial serum concentrations of lamotrigine showed a rapid reduction with ILE therapy and corresponded with clinical recovery, suggesting efficacy of ILE treatment in this case.

Massive lamotrigine and bupropion overdose resulting in status epilepticus without cardiovascular collapse

An 18 year-old woman presented to an outside hospital with seizure activity after a massive ingestion of lamotrigine, bupropion, trazodone, buspirone, and possibly isoretinoin. Her initial vital signs were remarkable for tachycardia (120 bpm). She was intubated for airway protection. For treatment of status epilepticus, she received a total of 12 mg of IV lorazepam along with a lorazepam infusion titrated to 15 mg/hr, a propofol infusion of unknown dosing, and phenobarbital 650 mg. She was transferred to a receiving hospital. Her initial ECG at the receiving hospital showed a QRS of 117 ms which narrowed with 50 mEq of sodium bicarbonate after approximately 6 hours. She required norepinephrine intermittently for blood pressure support for approximately 2 days. The patient had no dysrhythmias. EEG showed no epileptiform activity from approximately 11 hours–32 hours post ingestion. At the receiving hospital, her serum lamotrigine concentration was 109 mcg/mL (reference 3.0–14.0 mcg/mL) 7 hours after ingestion. Her bupropion concentration was 92 ng/mL (reference 50–100 ng/mL). She was extubated on hospital day 5 and discharged to a psychiatric facility on hospital day 13.

Management of lamotrigine overdose using hemodialysis

Lamotrigine [LTG] is primarily an anti-epileptic drug used to treat seizure disorders, depression, and bipolar disease. It is generally well tolerated with limited side effects reported during routine use. Adverse events after overdose include neurotoxicity in the form of sedation and seizure activity, as well as cardiopulmonary toxicity in the form of sodium-channel blockade and cardiovascular collapse. There is no consensus regarding the role of hemodialysis (HD) in management of lamotrigine toxicity. Based on pharmacological properties, LTG is a candidate for extracorporeal removal, however, the successful use of HD for the treatment of this poisoning is not well described. We report the case of a 44 year-old female after a LTG overdose that experienced prolonged sedation that was ultimately treated with HD with an excellent response.

Thorough QT/QTc in a Dish: An In Vitro Human Model That Accurately Predicts Clinical Concentration-QTc Relationships

"Thorough QT/corrected QT (QTc)" (TQT) studies are cornerstones of clinical cardiovascular safety assessment. However, TQT studies are resource intensive, and preclinical models predictive of the threshold of regulatory concern are lacking. We hypothesized that an in vitro model using induced pluripotent stem cell (iPSC)-derived cardiomyocytes from a diverse sample of human subjects can serve as a "TQT study in a dish." For 10 positive and 3 negative control drugs, in vitro concentration-QTc, computed using a population Bayesian model, accurately predicted known in vivo concentration-QTc. Moreover, predictions of the percent confidence that the regulatory threshold of 10 ms QTc prolongation would be breached were also consistent with in vivo evidence. This "TQT study in a dish," consisting of a population-based iPSC-derived cardiomyocyte model and Bayesian concentration-QTc modeling, has several advantages over existing in vitro platforms, including higher throughput, lower cost, and the ability to accurately predict the in vivo concentration range below the threshold of regulatory concern.

Lamotrigine ODT-Induced Seizure in a 3-Year-Old Child after Accidental Ingestion

Lamotrigine is a new generation antiepileptic which blocks sodium channels and can cause significant toxicity in overdose. A case of a three-year-old child who suffered a seizure and required endotracheal intubation after accidental lamotrigine ingestion is presented. The lamotrigine concentration measured 23.2 mcg/mL which is the highest reported after accidental pediatric exposure. A review of the literature regarding pediatric lamotrigine poisoning is also included.

Vertical gaze palsy due to medication error

We present a teenage boy with recent onset of seizures, who was erroneously treated with a large dose of an antiseizure medication as a result of drug mix-up. The ensuing drug toxicity caused vertical gaze palsy, an unusual manifestation related to overdose of the agent. Timely recognition of the error and discontinuation of the drug resulted in complete recovery to baseline.

Safety profile of lamotrigine in overdose

BACKGROUND

Lamotrigine is an anticonvulsant as well as a mood stabilizer. Apart from its established use in the treatment of epilepsy, there has been an expansion of its use in the treatment of mental disorders. Patients with epilepsy as well as those with mental disorders are at increased risk of deliberate drug overdoses. An evidence base for the safety profile of lamotrigine in overdose is an essential tool for prescribers. The objective of this study was to carry out a narrative synthesis of the existing evidence for the safety profile of lamotrigine in overdose.

METHODS

A systematic search was conducted of EMBASE (1974 to December 2015), MEDLINE (1946 to December 2015), PsycINFO (1806 to December 2015) and CINAHL (1981 to December 2015) databases. Studies were included in which there was a deliberate or accidental single drug overdose of lamotrigine, with its toxic effects described. Studies that did not involve an overdose were excluded. A narrative synthesis of the described toxic effects was carried out.

RESULTS

Out of 562 articles identified, 26 studies were included, mainly in the form of case reports and series. The most commonly described toxic effects of lamotrigine were on the central nervous system, specifically seizures, movement disorders and reduced consciousness. Other toxic effects included QTc interval and QRS complex prolongations, hypersensitivity reactions, serotonin syndrome as well as rhabdomyolysis possibly due to seizures and/or agitation. Deaths were recorded in two studies, with cardiovascular and neurological toxic effects described.

CONCLUSIONS

Even though lamotrigine has been reported to be well tolerated, there is a risk of toxic effects which can be life threatening in overdose. This needs to be borne in mind when prescribing to patients at an increased risk of deliberate drug overdose.

Unmasking of myoclonus by lacosamide in generalized epilepsy

Lacosamide is a new-generation antiseizure medication that is approved for use as an adjunctive treatment and monotherapy in focal epilepsy. Its use in generalized epilepsy, however, has not been adequately evaluated in controlled trials. We report a 67-year-old woman who experienced new-onset myoclonic seizures after initiation of lacosamide. We presume that she had an undiagnosed generalized epilepsy syndrome, likely juvenile myoclonic epilepsy. Myoclonic seizures were not reported before introducing lacosamide and completely resolved after lacosamide was discontinued. This suggests that lacosamide may have the potential to worsen myoclonus, similar to what has been reported with another sodium channel agent, lamotrigine, in some individuals with genetic generalized epilepsy (GGE).

Evolving Electrocardiographic Changes in Lamotrigine Overdose: A Case Report and Literature Review

Lamotrigine overdose usually follows a benign pattern, and the majority of cases reported involve a co-ingestant. Prior reports have suggested the possible use of intravenous lipid emulsion in cases of severe sodium channel blockade. We describe the electrocardiographic changes in a massive lamotrigine overdose treated with intravenous lipid emulsion. A 36-year-old male with bipolar disorder ingested 13.5 g of lamotrigine in a suicidal attempt. The lamotrigine level was 78.0 μg/mL. Comprehensive drug screen was negative for all screened compounds. The electrocardiogram demonstrated a prolonged QRS complex and signs suggestive of sodium channel blockade. Refractory to treatment with sodium bicarbonate was treated with intravenous lipid emulsion, with immediate resolution of the electrocardiographic changes. Lamotrigine inhibits the voltage-gated sodium channel opening, attenuating the release of excitatory neurotransmitters. Cardiac intraventricular conduction could be delayed in cases of lamotrigine overdose resulting in QRS and QTc prolongation and R waves >3 mm in leads I and aVR. A potential role for intravenous lipid emulsion therapy has been described in patients with toxic levels of lamotrigine and electrocardiographic changes refractory to the treatment with sodium bicarbonate. Intravenous lipid emulsion has been successfully used in the treatment of lamotrigine cardiac toxicity.

Rhabdomyolysis after lamotrigine overdose: a case report and review of the literature

BACKGROUND

Lamotrigine is an effective anticonvulsant drug that has also been demonstrated to be effective in the treatment of bipolar disorder. We report a case of rhabdomyolysis after intentional overdose in a woman aged 48.

CASE PRESENTATION

A 48-year-old female presented to the emergency department after an acute ingestion of 6 g of lamotrigine. The patient suffered from bipolar disorder, and she was taking lamotrigine and olanzapine. At that point, she had a major depressive episode, and she wanted to commit suicide. Activated charcoal was administered in the emergency department. Her vital signs were still normal, and she entered the Medical clinic, where she had been there for 2 days in a good condition. The hematological and biochemical results were normal. On the fourth day, the levels of creatine phosphokinase (CPK) showed remarkable increase (2500 IU/ml). Fluid and bicarbonate intravenous administration was performed, and CPK levels returned to normal after 3 days.

CONCLUSION

The majority of patients exposed to lamotrigine in overdose experienced no toxic clinical effects. The most common clinical effects are drowsiness and lethargy, vomiting, nausea, ataxia, dizziness/vertigo, and tachycardia. In this case report, the patient was alert and did not have any serious complications, except for mild rhabdomyolysis, which was the main consequence of lamotrigine overdose.

Mechanisms of sudden unexplained death in epilepsy

PURPOSE OF REVIEW

Human and experimental research has identified cardioautonomic and respiratory dysfunction as a frequent accompaniment in human and animal model events of sudden unexpected death in epilepsy (SUDEP). This review aims to provide an overview of the scientific evidence behind the currently accepted risk factors and working hypotheses regarding SUDEP pathophysiology.

RECENT FINDINGS

Epidemiological analysis of public health burden of SUDEP has shown that it rates second only to stroke in the years of potential life lost. Clinical and experimental studies uncovered the dynamic cardiorespiratory dysfunction interictally and imminently to SUDEP, and model systems have facilitated discoveries in SUDEP mechanistic understanding and application of pilot therapeutic interventions. Pilot molecular profiling of human SUDEP has uncovered complex genomic structure in the candidate gene network.

SUMMARY

Extensive clinical and experimental work has established a rationale for the conceptual thinking about SUDEP mechanisms. The application of the global molecular profiling will be invaluable in unraveling the individually unique genomic complexities and interactions that underlie the physiological signature of each patient. At the same time, sophisticated model systems will be critical in the iterative translation of human genetics, physiology, pharmacological interventions, and in testing preventive interventions.